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METHOD FOR SAMPLING AND EXTRACTING POLLUTANTS IN A FLUID, SAMPLING
CARTRIDGE, SAMPLING AND EXTRACTING DEVICES USING SAID METHOD

Abstract

A sampling cartridge (1), a sampling device (2, 3), an extracting device
(4) and a sampling and extracting device (5) which allow safe measurement
without contamination of the adsorbent, before or after sampling. The
sampling cartridge (1) comprises an envelope (10) made from an inert
material in which an adsorbent material (13) is sealed, in a leaktight
manner, by two caps (11, 12) located at the two ends (100, 101) of the
envelope. Each cap (11, 12) has an opening (111, 121) which is closed by
a seal (110, 120) formed of a silicone film and a barrier layer made of
aluminum which withstands the high temperatures necessary for the thermal
desorption technique. The cartridge (1) is conditioned under inert gas
and its ends (100, 101) comprise at least one seal-on end piece (102) for
a cap, and one universal end piece (105) for a sealed, screwed or
clip-fastened cap.

28. A method of sampling and extracting pollutants in a fluid, comprising
using a single sampling cartridge (1) to perform, during a first step,
sampling in a passive mode or in an active mode, and, during a second
step, extracting collected pollutants by thermal desorption and
circulating a carrier gas through the sampling cartridge (1), carrying
out the sampling step via the sampling cartridge (1) or of a sampling
device (2, 3, 5) containing the sampling cartridge (1), carrying out the
extraction step via an extracting device (4) or a sampling and extracting
device (5) containing the sampling cartridge (1), conditioning the
sampling cartridge (1) under an inert gas and comprising an envelope out
of an inert material, containing an adsorbent material (13), sealed in a
leaktight manner by two caps (11, 12) located at both ends (100, 101) of
the envelope (10, 10', 10''), and each cap (11, 12) having an opening
(111, 121) closed by a pierceable seal (110, 120) made of a silicone film
and at least one barrier layer.

29. The method of sampling and extracting according to claim 28, wherein,
to perform the sampling step in the passive mode, removing one of the
caps (11, 12) from the sampling cartridge (1) to open the envelope (10,
10', 10'') and permitting the fluid to be analyzed enter and, once the
sampling is obtained, again closing the envelope (10, 10', 10'') with one
of the caps (11, 12).

30. The method of sampling and extracting according to claim 28, wherein,
to perform the sampling step in the active mode or the extraction step,
leading the fluid to be analyzed or the carrier gas through the sampling
cartridge (1) via cannulas of the sampling device (2), of the extracting
device (4) or of the sampling and extracting device (5), to pierce
through the seals (110, 120) of the sampling cartridge (1).

31. A sampling cartridge (1) for implementing the method according to
claim 28, the sampling cartridge (1) comprising: the envelope (10, 10',
10'') made from the inert material, wherein the adsorbent material (13)
is placed and sealed, in a leaktight manner by the two caps (11, 12)
located at both ends (100, 101) of the envelope (10, 10', 10''), each cap
(11, 12) having an opening (111, 121) closed by the pierceable seal (110,
120) made of the silicone film and at least one barrier layer, and the
sampling cartridge (1) containing the adsorbent material (13) is filled
with the inert gas which is pressurized.

33. The sampling cartridge (1) according to claim 31, wherein the
envelope (10, 10', 10'') is made from glass.

34. The sampling cartridge (1) according to claim 33, wherein the
envelope (10, 10', 10'') is made from amber glass.

35. The sampling cartridge (1) according to 31, wherein the adsorbing
material (13) is a polymer.

36. The sampling cartridge (1) according to claim 35, wherein the polymer
has a shape of a solid stick positioned in a central section of the
envelope (10, 10', 10'') by at least one axial centering element (14).

37. The sampling cartridge (1) according to claim 28, wherein the at
least one barrier layer is made from aluminum or Teflon.TM..

40. The sampling cartridge (1) according to claim 33, wherein the
sampling cartridge (1) comprises a heating resistor integrated in its
glass envelope (10, 10', 10''), and the caps (11, 12) are made from metal
and form electrodes connected to the heating resistor.

41. An active sampling device (2) for implementing the method according
to claim 28, comprising a space (20) for the sampling cartridge (1),
wherein the sampling device (2) comprises a fixed cannula (21) and a
movable cannula (22) in translation arranged on either side of the space
(20), a means (23) for actuating the movable cannula (22) between a
retracted position and a sampling cartridge (1) piercing position, and a
system (207) for locking the movable cannula (22) in the piercing
position, and the first and second cannulas (21, 22) being connected to a
circuit for the fluid to be analyzed.

42. The sampling device (2) according to claim 41, wherein the actuating
means (23) comprises a return spring (206) for returning the movable
cannula (22) from the piercing position back to the retracted position.

43. The sampling device (2) according to claim 41, wherein the actuating
means (23) comprises a locking means (207) in the form of a chicane.

44. The sampling device (2) according to claim 41, wherein the first
cannula (22) is open towards external air and the second cannula (21) is
connected to a suction pump (25).

45. The sampling device (2) according to claim 41, wherein first cannula
(22) is connected to a water supply and the second cannula (21) to a
gravity discharge outlet.

46. The sampling device (2) according to claim 45, wherein a solenoid
valve is located upstream of the first cannula (22) connected to the
water supply.

47. The sampling device (2) according to claim 41, wherein the first and
the second cannulas (21, 22) end in a same water vial and a pump is
located between one of the first and the second cannulas and the vial.

48. The sampling device (2) according to claim 41, wherein one of the
first and the second cannulas comprises a mouthpiece.

49. A passive sampling device (3) for implementing the method according
to claim 28, comprising a hollow body (30) defining a space for the
sampling cartridge (1), wherein the hollow body (30) comprises a closed
end (300) and an open end (301), and the passive sampling device (3)
comprises two plugs (31, 32) mounted, in a removable manner, on the ends
(300, 301) so as to be interchangeable, a tight first plug (31) and an
open second plug (32) comprising a diffusion grid (320).

50. The passive sampling device (3) according to claim 49, wherein the
closed end (300) comprises a recess (302) closed by one of the first and
the second plugs (31, 32) to receive one of the caps (11, 12) of the
sampling cartridge (1) during the sampling step.

51. The passive sampling device (3) according to claim 49, wherein the
first plug (31) comprises a magnet (310) to fasten the device onto a
metallic support.

52. The passive sampling device for implementing the method according to
claim 28, comprising the sampling cartridge (1), wherein the sole
sampling cartridge (1) forms the passive sampling device and the passive
sampling device is equipped with a diffusion grid (15) arranged close to
an end (100, 101) of the envelope (10, 10', 10'') and with a tight cap
(11, 12) clipped or screwed on the end.

53. An extracting device (4) for implementing the method according to
claim 28, arranged between a carrier gas inlet and an analyzer,
comprising a hollow body (46) that defines a space for the sampling
cartridge (1) and a heating element (43) of the sampling cartridge (1),
wherein the extracting device (4) comprises a fixed cannula (40) and a
movable cannula (41) which is movable in translation arranged on each
side of the housing, a pusher (421) coupled with the movable cannula (41)
to move the movable cannula (41) between a retracted position and a
sampling cartridge (1) piercing position, and one of the first and second
cannulas (41) is intended for being connected to a carrier gas inlet and
the other of the first and second cannulas (40) is connected to an
injector of an analyzer.

54. A sampling and extracting device (5) for implementing the method
according to claim 28, wherein the sampling and extracting device (5)
comprises an extracting device (4) connected to a body (50) comprising a
suction pump (51) and an inert gas tank (52), one of the first and the
second cannulas (40) being connected through a solenoid valve (55) to the
suction pump (51), during the sampling step, or to the inert gas tank
(52), during the extraction step, and the other cannula (41) being
intended to be connected to an air inlet, during the sampling step, or to
an analyzer, during the extraction step.

Description

TECHNICAL SCOPE

[0001] The present invention relates to pollutants sampling in a fluid
such as air or water, carried out in compliance with specific standards
described in the literature.

[0002] The quality measurement of indoor ambient air generally applies to
the monitoring of: [0003] housing [0004] premises open to the public
[0005] offices

[0006] The quality measurement of running water relates to the water
distributed in housings and in all public places, but also to the surface
water of rivers, well water, etc.

[0007] These application examples are of course not limiting.

[0008] The present invention thus relates to a method for sampling and
extracting pollutants in a fluid, a sampling cartridge, various sampling
and extracting devices using said method.

STATE OF THE ART

[0009] Sampling of pollutants in the air is performed today actively or
passively. Pollutants mean for example the volatile organic compounds
(VOCs), which are organic compounds that can easily be found in gaseous
form in the atmosphere, but also any other type of substances harmful to
health such as pesticides, herbicides, acaricides, polycyclic aromatic
hydrocarbons (PAHs), etc.

[0010] In the case of passive sampling the sample is collected by means of
a sampling badge. The sampling badge is worn by a person or placed in a
room to be sampled and contains capsules provided with an adsorbent to
perform a passive pollutant collection by diffusion through a membrane.
Sampling can last from 8 hours to 4.5 days according to the exposure of
the persons and to the type of pollutants to be sampled.

[0011] In the case of active sampling, the sample is collected by means of
pumps connected to sampling tubes containing one or several selective
adsorbents according to the type of pollutants to be collected. These
adsorbents are traditionally in the form of a powder. After pumping a
known quantity of air or water through the tube that contains the
adsorbent used to trap the pollutants, the trapped pollutant is either
extracted using a very toxic solvent of the CS2 (carbon disulfide) type
or thermally desorbed with a thermal desorber.

[0012] The active sampling is generally carried out by means of a constant
flow pump connected to a two-segment tube provided with one or several
specific adsorbents of the activated carbon, Tenax.TM., chromosorb, etc.
types to trap the pollutants according to their nature and of the
expected concentrations.

[0013] The sampler connects the tube (trap) to the pump and sets the flow
recommended according to the pollutant and to the exposure concentration
tolerated by the legislator. The recommended sampling time is 24 hours
(French experimental standard XPX43-402). Of course, the volume to be
sampled and the flow to be respected are defined for every country in the
regulations in force.

[0014] After the sampling phase, the tube is opened at one end to remove
the adsorbent on which the pollutants have been collected. The two
segments are subjected to an extraction with a CS2-type solvent or with
benzyl alcohol before they are analyzed separately to check whether the
adsorbent has not been saturated on the first segment.

[0015] These systems have many drawbacks: [0016] Information is lost
during the extraction by means of the solvent, due to the dilution of the
sample, reproducibility is difficult because of the sampling mode: air
current, air flow control, adsorbent homogeneousness, etc. [0017] Sample
preservation and integrity are not guaranteed, as there is a risk of
contamination of the adsorbent to be analyzed since the adsorbent is put
into contact with the exterior environment between the collection and the
analysis. [0018] Some compounds remain adsorbed on the adsorbent. [0019]
The extraction requires the use of polluting solvents. [0020] The time
required for the extraction is very long. [0021] The price remains high.

[0022] The thermal desorption extraction technique is more efficient and
sensitive. It is generally used within the framework of the active
sampling by pumping on stainless steel or glass cartridges containing an
adsorbent held in place by quartz wool. A double sampling or the division
of the gas flow during desorption and the recollection of 50% in a
retention tube is generally necessary to keep a reference sample. This
technique requires systematic conditioning and control of the tubes prior
to their use. The preservation after sampling requires using tube sealing
caps whose tightness often is questionable. The tubes show large
dispersion with respect to the pressure drop of every tube before and
during sampling. The tubes cannot be used for sampling liquids. The
internal dead volume is very important and reduces the sensitivity.

[0023] On the other hand, for passive sampling badges as well as for
active sampling tubes, it is always necessary to open the ends to perform
the sampling and then to re-close them to transfer the sampling badge or
tube to the laboratory and carry out a gas chromatography or mass
spectrometry analysis.

[0024] This multiple handling to open and close the sampling badges or
tubes by means of plastic capsules or caps, caps equipped with an o-ring
or closing systems with a mechanical sealing cone do not allow ensuring a
perfect tightness of these sampling devices from the measuring site up to
the laboratory.

[0025] Cross-contaminations between the sampling devices and the
associated systems are recurrent and well known by the persons skilled in
the art. Since these sampling systems are reusable, the operator must
consequently condition them for hours, prior to the sampling and after
the analysis, under an inert gas flow and continuous heating in order to
purify them. Then, the operator must carry out a blank test of a batch of
sampling devices to define their degree of purity before he carries out
the actual on-site sampling.

[0026] On the other hand, the use of classic adsorbents such as Tenax.RTM.
or activated carbon in real conditions shows that, according to the
degree of humidity on the sampling sites, the adsorbent soaks up water,
compacts and closes up to be eventually saturated with water and let the
molecules searched for pass through. Moreover, the sampling tubes are
generally entirely filled with adsorbents, which considerably reduces
their internal volume and makes impossible a homogeneous interaction
between the air or gas flow and the adsorbent to ensure proper sampling.
As the tubes are always open during the sampling phase, the air flow
necessarily escapes at one of its ends, further reducing the chances to
achieve a representative sampling.

[0027] Publications EP 0 042 683 A1 and U.S. Pat. No. 5,574,230 illustrate
two examples of this type of sampling tubes closed at their ends by
removable caps rendered tight by o-rings or the like, which must be
opened during the sampling phase, then closed, and opened again during
the analysis phase.

[0028] Publication U.S. Pat. No. 6,167,767 B1 describes another sampling
tube type whose ends are closed by a pierceable cover held by a cap
crimped around an o-ring, each cap being provided with a central opening
to receive a sampling needle of an automated sequential gas sampling
machine. Even if, in this example, the tightness of the sampling tube is
preserved before and after sampling, it is reduced to zero when analyzing
the sample on a thermal desorption machine which requires removing the
crimped caps.

[0029] Publication DE 10 2006 025 932 B3 describes a laboratory analysis
device using a metal vial wherein a steel or glass tube containing a
sample or an adsorbent to be analyzed is introduced. The end of the vial
and of the tube is closed by a tight and pierceable cover, held by a
screw cap, provided with a central opening crossed by two needles of an
automatic thermal desorber to allow the circulation of a carrier gas
around and through the tube. This device is not intended for carrying out
on-site samplings and requires the handling of the sample tube before and
after the analysis, with high risks of operator contamination.

[0030] Publication JP 2009 053121 A also describes a laboratory analysis
device for solid samples put in a crucible placed in a high-temperature
oven. The generated gases are trapped in highly heat-resistant glass
tubes provided with an adsorbent to retain the gases and closed at the
ends by simple highly heat-resistant flexible plugs that can be pierced
by the needles of an automatic thermal desorber allowing the circulation
of a carrier gas through the tube. This tube is therefore not intended
for carrying out on-site sampling and its tightness is not guaranteed.

DESCRIPTION OF THE INVENTION

[0031] The purpose of the invention is to offer a totally secure, reliable
and reproducible sampling and extracting method thanks to the use of a
ready-to-use single-use sampling cartridge that can be used on its own or
in a dedicated sampling device, and that can feed a known or a dedicated
extracting device, thus allowing a safe measurement without contamination
of the adsorbent neither before nor after the sampling, as the cartridge
allows carrying out all process steps from the sampling up to the
analysis, and it can easily be stored and transported without loss of
information. In particular, the sampling cartridge can be inert, traced
and recyclable, allowing performing either active or passive samplings.

[0032] To this purpose, the method for sampling and extracting pollutants
in a fluid is characterized in that one uses one and the same sampling
cartridge to perform in a first step said sampling in passive mode or in
active mode, and in a second step the extraction of the collected
pollutants by thermal desorption and circulation of a carrier gas through
said cartridge, the sampling step being carried out by means of the sole
sampling cartridge or of a sampling device containing said cartridge, and
the extraction step being carried out by means of an extracting device or
of a sampling and extracting device containing said cartridge, said
cartridge being conditioned under inert gas and comprising an envelope
out of an inert material, containing an adsorbent material, sealed in a
leaktight manner by two caps located at both ends of the envelope, each
cap having an opening closed by a pierceable seal made of a silicone film
and at least one barrier layer.

[0033] Advantageously, to perform the sampling step in passive mode, one
removes one of the caps from said cartridge to open the envelope and let
the fluid to be analyzed enter and, once the sampling is made, on closes
the envelope again with said cap.

[0034] Advantageously, to perform the sampling step in active mode or the
extraction step, one leads the fluid to be analyzed or the carrier gas
through the cartridge by means of cannulas of the sampling device, of the
extracting device or of the sampling and extracting device, to pierce the
ends of said cartridge through said seals.

[0035] Also to this purpose, the sampling cartridge according to the
invention comprises an envelope, for example a cylindrical envelope, out
of an inert material, in which an adsorbent material is placed, sealed in
a leaktight manner by two caps located at both ends of the envelope, each
cap having an opening closed by a seal made of a silicone film and at
least one barrier layer out of aluminum or Teflon.TM.
(polytetrafluoroethylene PTFE), said cartridge being filled with a
pressurized inert gas. The use of a specific film out of silicone and
aluminum or out of aluminum/silicone/aluminum allows withstanding the
high temperatures necessary for the thermal desorption technique, namely
between 250.degree. C. and 350.degree. C. The silicone has a re-sealing
ability that allows closing a hole that would be made in it. Aluminum has
a barrier effect that allows achieving perfect tightness against the most
volatile molecules. Teflon.TM. can replace aluminum for a similar result.
The adsorbent material is thus totally isolated from the exterior
environment thanks to a controlled and efficient tightness. The film also
allows limiting the uncontrolled introduction of air at the completion of
an active sampling. On the other hand, aluminum or Teflon.TM. is neutral
towards the traces to be analyzed. The cartridge is preferably
conditioned under inert gas (for example argon, which is heavier than
air) in order to prevent any cross-contamination with the exterior
environment. To date, no adsorption tube for the environmental field is
conditioned under inert gas.

[0036] Offering the sampling system in the form of a cartridge allows
adding a solvent such as dichloromethane to perform an extraction,
preferably by shaking the cartridge. The extract will not come into
contact with the air of the laboratory and cross-contamination will be
impossible, unlike the systems currently on the market. After the
extraction phase, injection can take place on a LC-MS system (liquid
chromatography coupled with mass spectrometry), for example to dose the
medicines or endocrine disruptors in the water. The solvent extraction
technique directly in the cartridge can also be suitable for other
applications such as dosing of allergens, narcotics, drugs or explosives.
The geometry of the cartridge can be adapted to allow transferring it
directly on the sample racks of the various automatic analyzers.

[0037] Advantageously, the envelope of the cartridge is preferably made of
glass. The glass is amber or transparent. The use of amber glass avoids
the degradation of photosensitive molecules collected. One will use
preferably a type 1 borosilicate amber glass. The superficial treatment
of the glass (passivation or deactivation) also allows lowering the
detection limits of certain molecules such as those of the pesticides.
The glass walls of the envelope can be coated with a film (deposit of a
selective phase of the silicone or PDMS (polydimethylsiloxane) type) with
a suitable selectivity and film thickness. After the phase deposit, the
cartridge is sealed under inert gas.

[0038] The adsorbent material is advantageously a polymer. The cartridge
contains a full polymer, hereinafter canned solid polymer to
differentiate it from a powder polymer. It can also be a polymer in the
form of a powder or polymer-coated glass balls, an adsorbent of the
activated carbon or graphite type, a porous polymer of the Tenax.TM.
type, a diatomite or a clay, any microporous adsorbent carrier,
miniaturized sensors, paper carriers impregnated with a reagent or
colorimetric indicators, agars. One shall prefer the use of a solid,
hydrophobic polymer, with high adsorption capacity, such as for example a
solid and inert organomineral polymer of the siloxane family. It will be
single-use, ready-to-use and will form a consumable. It can have the
shape of a for example cylindrical stick positioned inside the tube by
means of one or two axial centering elements. The centering element is a
metal grid with a known and regular porosity, for example 200 .mu.m,
provided with a central hole equal to the diameter of the polymer stick
(cylinder) allowing positioning axially the polymer in the center of the
cartridge and at equal distances from the walls of the glass envelope.
This technique will allow a homogeneous exchange of the gaseous or liquid
phase with the polymer during the adsorption phase.

[0039] Advantageously, one of the caps is crimped on the envelope of the
cartridge and the other cap is crimped, clipped or screwed on the
envelope. The cartridge then has a crimp-on end piece with a diameter of
for example 11 mm on one side, and for example a 11 mm clip-on end piece
on the other side, allowing the use of clip-on caps, but also of crimp-on
caps. It can also comprise a universal end piece allowing the use of
screw-on, clip-on or crimp-on caps. This configuration allows opening the
cartridge without using specific tools for removing the polymer if
necessary or for carrying out a passive sampling.

[0040] Advantageously, the envelope of the cartridge is made of a reusable
material, for example if the tube is made of glass. One thus obtains a
single-use device which is partly recyclable and therefore
environmentally friendly. The glass cartridge can be recycled by the
manufacturer. The product is environmentally friendly and reusable after
having extracted the caps and cleaned and decontaminated the glass.

[0041] The cartridge can advantageously comprise an individual
traceability marking.

[0042] It can also comprise a heating resistor integrated in its glass
envelope, and the caps can be out of metal to form electrodes connected
to said heating resistor, for the thermal desorption step.

[0043] For the purpose stated above, the invention also relates to a
sampling device comprising a space for a sampling cartridge as defined
above, characterized in that it comprises a fixed cannula and a cannula
movable in translation arranged on either side of the space, a means for
actuating the movable cannula between a retracted position and a
cartridge piercing position, and a system for locking the movable cannula
in piercing position, said cannulas being connected to a circuit for the
fluid to be analyzed. The cartridge does not need to be opened, as
sampling will take place via the cannulas. The use is therefore easy.

[0044] Advantageously, a cannula is mounted on a removable fitting. This
allows easy dismounting and cleaning of the cannula.

[0045] The cannula has advantageously a tapered tip with at least one side
bore. This prevents clogging by the cartridge seal.

[0046] The actuating means advantageously comprises a return spring. The
spring allows the movable cannula to move back to a retracted position
when it is released from the piercing position.

[0047] The actuating means advantageously comprises a locking system using
a chicane. The cannula is locked in piercing position by the actuating
means itself.

[0048] According to a particular arrangement, the device comprises a
charge level indicator of a battery provided to power a fluid suction
pump. This indicator will for example be a LED.

[0049] According to another arrangement, the device comprises an
interruption indicator for the power supply of said pump. This will allow
identifying wrong measurements. This indicator can be made of a LED.

[0050] It advantageously comprises an indicator of the selected
incrementation time.

[0051] According to a first variant, one of the cannulas is open towards
the external air and the other is connected to a suction pump. This
variant allows measuring air pollution in a room or in a given
environment.

[0052] According to a second variant, one of the cannulas is connected to
a water supply and the other to a gravity discharge outlet. This variant
allows for example analyzing and measuring the pollution of the tap water
distributed daily to millions of homes. A specific housing to be screwed
on the water tap outlet is then provided. Once it is screwed in place, it
will be sufficient to switch on or arm the double-needle sampling device
to let tap water flow through the cartridge and concentrate the present
pollutants on the adsorbent material. It can also be equipped with a
device to measure or check the water flow that passed through the
sampling cartridge.

[0053] A solenoid valve is advantageously located upstream of the cannula
connected to the water supply. This solenoid valve can comprise a delay
time in order to define a quantity of water to be analyzed.

[0054] According to a third variant, the cannulas end in a same water vial
and a pump is located between one of the cannulas and the vial. The water
circulates then in a closed circuit, making it possible to work over a
non-limited time.

[0055] According to a fourth variant, one of the cannulas comprises a
mouthpiece. This allows analyzing the expired air. A single-use
mouthpiece (of the alcoholmeter type) will be screwed on the sampling
device containing the sampling cartridge. This device will allow
concentrating the air expired by a person in order to concentrate
possible markers or metabolites allowing identifying certain forms of
cancer. The expired air passes through the sampling cartridge containing
the polymer or a specific adsorbent material to be concentrated there
before being evacuated through a cannula with a large inner diameter
located at the outlet of the cartridge. The patient will have to repeat
the blowing several times, according to various criteria. The system can
be equipped with a device to measure or check the air flow that passed
through the sampling cartridge. After the sampling phase, the cartridge
will be analyzed by thermal desorption or extraction followed by a GC-MS
or LC-MS (gaseous or liquid chromatography coupled with mass
spectrometry) identification.

[0056] The invention also relates to a passive sampling device, said
device comprises a hollow body defining a space for a sampling cartridge
as defined above, characterized in that the hollow body comprises a
tightly closed end and an open end, the device comprises two plugs
mounted in a removable manner on said ends so as to be interchangeable, a
first tight plug and a second open plug comprising a diffusion grid. With
this device, the cartridge is introduced in the hollow body, which is
specific and can be worn by an operator thanks to a clip, fastened onto a
metallic background with the magnet or be suspended with a ring attached
to the clip. The device can be provided with all these accessories as the
sampling height is very important. Before use, the tight cap must be
removed from the cartridge, then the tight plug must be exchanged with
the plug equipped with the diffusion grid. During sampling, the air will
pass through the diffusion grid, which can be made of stainless steel,
which allows obtaining a controlled passage through a standardized
opening. After sampling, the tight cap is put back in place on the
cartridge and the plug with the seal is screwed on the device. This
passive sampling device has the advantage of offering double tightness
and double functionality. The closed end of the hollow body
advantageously comprises a recess closed by one of the plugs to receive
one of the caps of the cartridge during the sampling step. So the device,
in addition to serving for collecting the sample, also keeps the tight
cartridge cap in the plug until completion of the sampling. The seal
ensures the tightness of the device when sending the whole to the
laboratory. This sampling device ensures the preservation of the
collected sample. The tight plug can comprise a magnet to fasten said
device onto any metallic support.

[0057] The invention also relates to a passive sampling device comprising
a cartridge as defined above, characterized in that the cartridge is
equipped with a diffusion grid arranged close to an end of the envelope
and with a tight cap clipped or screwed on said end. It is therefore
possible to use the cartridge itself as a sampling device by removing the
removable cap to perform the sampling and putting it back in place once
the sampling is completed.

[0058] The invention also relates to an extracting device arranged between
a carrier gas inlet and an analyzer, and comprising a hollow body that
defines a space for a sampling cartridge as defined above, and a heating
element of the cartridge, characterized in that it comprises a fixed
cannula and a cannula movable in translation arranged on each side of the
housing, a pusher coupled with the movable cannula to move it between a
retracted position and a cartridge piercing position, one of the cannulas
being intended for being connected to the carrier gas inlet and the other
cannula being intended for being connected to the injector of an
analyzer. The movable cannula is advantageously actuated by screwing. The
cannula can therefore easily be pressed into the cartridge to be
analyzed. The carrier gas is thus injected on one side by a cannula to
extract the elements to be analyzed and exits on the other side through
the other cannula connected to the injector of an analyzer. The carrier
gas, with the elements to be analyzed, arrives this way to the analyzer
without external contamination.

[0059] The invention also relates to a sampling and extracting device,
characterized in that it comprises the above extracting device connected
to a body comprising a suction pump and an inert gas tank, one of the
cannulas being connected through a solenoid valve to said suction pump
during the sampling step or to said inert gas tank during the extraction
step, and the other cannula being intended to be connected to an air
inlet during the sampling step or to an analyzer during the extraction
step. This way, the cartridge as defined above can be put into the device
which, in sampling mode, will be able to suck in for example the exterior
air thanks to the pump; once sampling is completed, the cartridge will be
heated and the gas contained in the cartridge will be re-injected in an
analyzer.

[0060] Further advantages will appear to the persons skilled in the art
when reading the examples below, illustrated by the attached figures,
which are given for illustrative purposes.

BRIEF DESCRIPTION OF THE DRAWINGS

[0061] FIG. 1 is a cross-section of a first example of a cylindrical
envelope of the cartridge according to the invention,

[0062] FIG. 2 is a cross-section of a second example of a cylindrical
envelope of the cartridge according to the invention,

[0063] FIG. 3 is a cross-section of a third example of a cylindrical
envelope of the cartridge according to the invention,

[0064] FIG. 4 is a perspective view of a cap of the cartridge according to
the invention,

[0065] FIG. 5 is a cross-section of a first embodiment of a sampling
device according to the invention,

[0066] FIG. 6 is the detail of the cannula of the device of FIG. 5,

[0067] FIG. 7 is the detail of the tip of the cannula of FIG. 6,

[0068] FIG. 8 is a perspective view of the device of FIG. 5.

[0069] FIG. 9 is a cross-section of a second embodiment of a sampling
device according to the invention in sampling position,

[0070] FIG. 10 is a cross-section of the second embodiment of a sampling
device in transport position,

[0071] FIG. 11 is a cross-section of the extracting device according to
the invention,

[0072] FIG. 12 is a cross-section of a passive sampling cartridge,

[0073] FIG. 13 is a cross-section of the sampling and extracting device
according to the invention, and

[0074] FIG. 14 is a perspective view of FIG. 13.

ILLUSTRATIONS OF THE INVENTION AND VARIOUS WAYS OF REALIZING IT

[0075] Sampling cartridge 1 according to the invention comprises a
cylindrical envelope 10, 10', 10'', two caps 11 and 12 arranged on either
side or at every end 100, 101 of envelope 10, 10', 10'' and an adsorbent
material 13 placed inside of envelope 10, 10', 10''. Envelope 10, 10',
10'' can be made of amber or transparent glass. Amber glass has the
advantage of protecting adsorbent material 13 and the adsorbed
photosensitive molecules from the light. Glass in general also has the
advantage of being an inert material and to have an excellent heat
conductivity, thus reducing the duration of the thermal desorption. This
envelope 10, 10', 10'' of cartridge 1 is preferably cylindrical, but it
can have other cross-sections, for example square, hexagonal, ovoid, etc.
according to the applications. Adsorbent material 13 will be for example
a single-use, ready-to-use solid polymer or specific adsorbents allowing
trapping in a universal manner all types of pollutants. Caps 11 and 12
are sealed in a leaktight manner on envelope 10, 10', 10''. They can also
be screwed, clipped or crimped according to the applications. Closing
must preferably withstand high temperatures, namely up to 350.degree. C.
and have specific containment properties and excellent neutrality.

[0076] If a solid polymer is used, it can be single-use and ready-to-use.
One shall choose preferably a hydrophobic polymer, with high adsorbent
capacity, such as for example a solid and inert organomineral polymer of
the siloxane family. It can have the shape of a for example cylindrical
stick, which has the advantage of presenting no resistance to the passage
of the fluid and generating only very little pressure drop, or even no
pressure drop at all. It will preferably be positioned by means of one or
two axial centering elements 14 in envelope 10, 10', 10''. Centering
element 14 is for example a metal grid with a known and regular porosity,
for example 200 .mu.m, provided with a central hole equal to the diameter
of the polymer (cylinder) allowing positioning axially the polymer in the
center of envelope 10, 10', 10'' and at equal distances from its walls.
This technique allows a homogeneous exchange of the gaseous or liquid
phase with the polymer during the adsorption phase. Any other centering
means may also be suitable, the main thing being that it does not hinder
the circulation of the fluid and the interaction with the polymer, and
that the contact surface with the polymer is as small as possible or even
punctual.

[0077] Cartridge 1 can also contain a polymer in the form of a powder or
glass balls coated with a polymer, an adsorbent of the activated carbon
or graphite type, a porous polymer of the Tenax.TM. type, a diatomite or
a clay, any microporous adsorbent carrier, but also miniaturized sensors,
paper carriers impregnated with a reagent or colorimetric indicators,
agars. Cartridge 1 can also contain an association of several capillary
sections containing phases or adsorbents and arranged axially through
centering element 14. The air will circulate through multi-selective
capillaries and the pollutants will be trapped in this specific device.

[0078] Cartridge 1 can also contain a gelose for microbiological analyses.
Legionella dosage may possibly be considered.

[0079] It is also possible to mount serially several cartridges containing
the same trap or traps of different natures to increase selectivity when
sampling unknown substances.

[0080] The dimensioning of cartridge 1 and of adsorbent material 13 with
respect to each other is optimized to reduce the internal volume of
cartridge 1, eliminate dead volumes, have only little or no inertia at
all, and thus increase the sensitivity of cartridge 1.

[0081] Cartridge 1 is preferably advantageously conditioned under inert
gas, for example argon, which is heavier than air, in order to prevent
any cross-contamination with the exterior environment. Conditioning
cartridge 1 under inert gas allows filling its internal volume with inert
gas, pressurizing seals 110, 120 that close its ends. This
overpressurization forms an indicator that allows checking the presence
of a pressure in cartridge 1 and thus checking the tightness of cartridge
1 before using it.

[0082] The sealing of cartridge 1 is consequently carried out in the
factory, under inert gas, by specific machines allowing controlling the
force applied during the crimping operation for the concerned caps. One
uses caps 11, 12 with a specific seal 110, 120 made of a
silicone/aluminum or aluminum/silicone/aluminum membrane or of any other
combination of equivalent materials, which withstands the high
temperatures required for the thermal desorption technique, namely
between 250.degree. C. and 350.degree. C. The neutrality of aluminum with
regards to the traces to be analyzed is advantageous, and the barrier
effect of aluminum allows achieving a perfect tightness against the most
volatile molecules. Aluminum can be replaced with Teflon.TM., which has
substantially the same properties. These seals 110, 120 can be made of a
composite membrane, of a superposition of material layers, etc. Each cap
11, 12 comprises an external section out of metal with a hole 111, 121
closed by seal 110, 120. Seal 110, 120 can be pierced by a cannula. This
seal 110, 120, which comprises silicone, has the advantage of being
tightly resealable after removal of the cannula, therefore always
ensuring the tightness of cartridge 1 after sampling.

[0083] Envelope 10 of cartridge 1 illustrated in FIG. 1 is mixed: on side
100 it comprises a crimp-on end piece 102 and on the other side 101 a
screw-on end piece 103.

[0084] Envelope 10' of cartridge 1 illustrated in FIG. 2 is of the mixed
type: on side 100 it comprises a crimp-on end piece 102 with a diameter
that can be for example 11 mm, and on the other side a clip-on end piece
104 provided with an 11 mm double ring 101 allowing the use of clip-on
caps 11, 12, but also of crimp-on caps.

[0085] Envelope 10'' of cartridge 1 illustrated in FIG. 3 is also of the
mixed type allowing all combinations of caps 11, 12: on side 100 it
comprises a crimp-on end piece 102, on the other side 101 a universal end
piece 105 combining a crimp-on end piece 102 a screw-on end piece 103
and, between both, a clip-on end piece 104 allowing the use of clip-on,
screw-on or crimp-on caps 11, 12. Envelope 10'' can replace the two other
envelopes 10, 10'.

[0086] The various end pieces 102, 103, 104, 105 described are an integral
part of glass envelope 10, 10', 10'' since they are made during its
manufacture, allowing ensuring the resistance and integrity of the
envelope and consequently of cartridge 1.

[0087] These various end piece configurations thus allow opening cartridge
1 without using specific tools to remove adsorbing material 13 if
necessary.

[0088] Cartridge 1 can comprise an envelope 10, 10', 10'' whose walls are
out of glass coated with a film (deposit of a selective phase of the
silicone or PDMS type) with a suitable selectivity and film thickness.
After the phase deposit, cartridge 1 is sealed under inert gas in the
factory, as stated previously. This envelope 10, 10', 10'' can be re-used
several times.

[0090] The identification, follow-up and traceability of cartridge 1 will
be possible, as it can be marked either by engraving (not represented) a
QR code or a bar code with a laser, or by means of a label withstanding
temperatures above 400.degree. C., or by other identification means, for
the follow-up of the production batch and its use during implementation.
Cartridge 1 can contain a transponder (not represented) for easy
identification during its whole duty cycle, that is to say from the
sampling to the storage, up to the analysis.

[0091] Calibration and standardization of ready-to-use cartridge 1 is
possible. A kit of calibrated sampling cartridges can be offered in order
to allow a quantification of the sampled pollutants. The polymers will be
isotopically labeled in order to avoid possible cross-contamination
errors. The series of 50 ng, 100, 200, 500, 1000 ng standards will also
include a blank and a tube containing quartz wool.

[0092] Calibration by the user is also possible. The fact of supplying the
sampling system in the form of cartridges 1 sealed on both sides by a
seal out of silicone/aluminum or aluminum/silicone/aluminum or out of any
other equivalent combination allows the user to inject his own standard
in cartridge 1 through seal 111, 121 using a suitable syringe.

[0093] As stated previously, cartridge 1 containing the solid polymer is
not subject to pressure drops and therefore to flow variations due to the
clogging of the classical polymers or adsorbents in powder form under the
influence of the degree of humidity present during sampling, hence
sampling regularity and accuracy.

[0094] Adsorbent material 13 can also be grafted or soaked with a
derivating agent of the DNPH type for formaldehyde analysis.

[0095] The use of amber glass avoids the degradation of photosensitive
molecules. The superficial treatment of the glass (passivation or
deactivation) also allows lowering the detection limits of certain
molecules such as those of the pesticides.

[0096] The use of an adsorbent material such as ready-to-use solid
polymers allows retaining a control sample prior to the analysis. It is
possible to use several polymers and to retain one as a control sample or
to cut a polymer in two equal parts prior to the analysis.

[0097] Sampling can be performed in active mode by means of a sampling
device 2 according to the invention illustrated in FIGS. 5 to 8. Sampling
device 2 comprises a housing 2' wherein a space 20 is arranged for a
ready-to-use sampling cartridge 1 according to the invention, this space
20 being accessible from the outside of housing 2'. It also comprises a
fixed cannula 21 and a cannula 22 movable in translation arranged on
either side of space 20, an actuating means 23 for moving movable cannula
22 between a retracted position and a cartridge 1 piercing position.

[0098] Each cannula 21, 22 represented in detail in FIGS. 6 and 7 is
mounted on a ring 220, 210 of the Luer type and ends with a tapered tip
with one side bore or several side bores 221, 211.

[0099] Fixed cannula 1 is placed at one of the ends 200 of space 20 with a
nut 205. A compression spring 202 is arranged around fixed cannula 21,
resting on end 200 on one side and on cartridge 1 on the other side. It
is guided axially in a recess of housing 2'. Two washers 203 and 204 can
be placed on either side of spring 202. Spring 202 will facilitate the
extraction of cartridge 1 from sampling device 2. Fixed cannula 21 is
connected to a suction pump 25.

[0100] Movable cannula 22 is placed at the other end 201 of space 20; it
is integral with actuating means 23, which includes a locking means 207
and a return spring 206. This actuating means 23 is made of a knurl in
the represented example. Locking system 207 is made here of a pin 207a
sliding in a track 24 provided in housing 2' of sampling device 2 (see
FIG. 8). Track 24 forms a S-shaped chicane that defines two stable
positions of movable cannula 22: a retracted position wherein it stands
back with respect to space 20 and allows introducing and removing
cartridge 1, and a piercing position wherein it protrudes inside of space
20 and communicates with the internal volume of cartridge 1 after having
pierced one of seals 110, 120. Any other equivalent actuating and locking
means can be suitable. Return spring 206 is resting on end 201 on one
side and on a shoulder 230 of actuating means 23 on the other side. It is
guided axially in a recess of housing 2'.

[0101] Sampling device 2 also comprises a control 250 for adjusting the
discharge of pump 25 and an outlet 251 for evacuating the air or the
water or any other fluid to be analyzed. Pump 25 is powered by a battery
252 arranged in housing 2' of sampling device 2. It can also include a
charge level indicator for battery 252. If, during sampling, battery 252
reaches a too low charge level, which would not allow completing the
planned sampling, the operator will be informed of the interruption of
the sampling during the sample collection cycle, for example by means of
a red LED. Sampling device system 2 can also comprise a preselection of
fixed pre-programmed times, but it can also allow creating a more complex
sampling cycle by means of an external software and a communication port
on sampling device 2 to drive the operation of pump 25. It can finally
comprise magnets 26 to allow fastening it on a metal surface or clips to
hang it on the belt, or any other fastening means, according to the
applications.

[0102] Sampling device 2 operates in active mode as follows: one places
ready-to-use cartridge 1 in space 20, on pushes with actuating means 23
movable cannula 22 towards cartridge 1, which will move until it reaches
fixed cannula 21, then compress spring 202, this will have the effect of
piercing cartridge 1 at each of its two ends, one locks the piercing
position of actuating means 23, and then one starts pump 25 to circulate
the air or the water, or any other fluid to be analyzed, through
cartridge 1, according to determined sampling parameters (flow and
sampling time). After the active sampling step, one unlocks actuating
means 23 to release cartridge 1 from fixed cannula 21 and movable cannula
22, which allows removing cartridge 1 to perform its analysis on site or
in a laboratory. Thus, the use of cartridge 1 according to the invention
is very practical, secure, without risk of operator or environmental
contamination since the operator is never in contact with the analyzed
fluid. Moreover, seals 110, 120 of cartridge 1 close up automatically in
a tight manner after the removal of cannulas 21, 22, allowing storage in
ambient air or cool storage, transport, handling of cartridge 1, without
loss of information, even over several weeks, up until the analysis step.

[0103] This sampling device 2 can easily be automated. In this case, it is
completed with a microprocessor and specific software, which control pump
operation according to a program to perform sampling either in continuous
mode or in sequential or pulsed mode. This sequential or pulsed mode
allows trapping the fluid to be analyzed in cartridge 1 and letting it
interact with adsorbent material 13 for a defined duration before
expelling it and repeating the cycle. This operating mode is unique and
very promising.

[0104] Sampling can also be performed in a passive way with sampling
device 3 according to the invention illustrated in FIGS. 9 and 10.
Sampling device 3 comprises a hollow body 30 that defines a space for
receiving a ready-to-use cartridge 1 according to the invention, two
threaded ends 300 and 301, a tight plug 31 and an open plug 32 equipped
with a clipped-on diffusion grid 320. One of the ends 300 is closed while
the other 301 is open. Closed end 300 comprises a recess 302. The two
plugs 31 and 32 are interchangeable, that is to say that they can be
placed equally on each of ends 300 and 301. Sampling device 3 is equipped
with a clip 33 to allow hanging it on the belt or with any other
fastening means. Tight plug 31 comprises a magnet 310 on the side
opposite to the threaded side, and a seal 311 inside of the threaded
section. Magnet 310 allows fastening sampling device 3 on a metal
background or support.

[0105] To perform passive sampling, one unscrews open plug 32 of sampling
device 3 provided with diffusion grid 320, one removes the clipped or
screwed cap 11 of ready-to-use cartridge 1 to open envelope 10 and let
the air enter, one arranges cartridge 1 in hollow body 30, one screws
open plug 32 back in place on end 301, one unscrews tight plug 31 to
place cap 11 of cartridge 1 in recess 302 of body 30, and one screws
tight plug 31 back in place on end 300 (FIG. 9). One can carry sampling
device 3 with the help of the clip, or fasten it magnetically on a metal
support, or put or hang it in the room to be analyzed. Once sampling is
completed after a duration determined between 8 hours and 4.5 days, one
unscrews plugs 31 and 32, one puts cap 11 back in place on cartridge 1,
which remains inside of body 30, one inverts plugs 31 and 32, and one
screws tight plug 31 on open end 301 and open plug 32 on end 300. This
ensures a double protection of cartridge 1 against external elements
thanks to its cap 11 topped by tight plug 31, and it can be transported
without any risk in sampling device 3 to the analysis place.

[0106] Passive sampling can also be performed with a ready-to-use
cartridge 1 according to the invention as that of FIG. 12. In this
cartridge 1, one inserted a diffusion grid 15 at one of the ends 101 of
envelope 10' of cartridge 1 of FIG. 2 for example. Cartridge 1 can
comprise a fastening clip (not represented) to allow carrying it on the
waist or hanging it on a support, or any other suitable fastening means.
To perform sampling passively one removes cap 12 clipped on end piece 104
to open envelope 10' and let the air enter. Once sampling is completed
after a duration determined between 8 hours and 4.5 days, one closes
envelope 10' with cap 12. Cartridge 1 is sealed again and can be stored
and transported without any risk to the analysis place. On can also use
envelope 10 or 10'' of cartridge 1 of FIG. 1 or 3 according to the type
of cap 12.

[0107] Once sampling is performed, the results must be extracted, and one
can use for that purpose an extracting device 4 according to the
invention as shown in FIG. 11. Extracting device 4 comprises a hollow
body 46 that defines a space for receiving a cartridge 1 according to the
invention used during an active or passive sampling. It moreover
comprises a fixed cannula 40, a movable cannula 41 integral with a plug
42, a heating element 43 arranged in hollow body 46 to surround cartridge
1, an insulator 44 preferably out of ceramic arranged around heating
element 43, and a connector 45 for the electrical power supply of heating
element 43. Hollow body 46 comprises on its external wall fins 48
allowing heat dissipation. Fixed cannula 40 is placed in a needle holder
400 placed in hollow body 46 and connected to an injection end piece 47
through a septum 401 of an analyzer. Movable cannula 41 is connected to
plug 42 by an elastic ring 420 and to a pusher 421 located inside of plug
42 that allows perforating seals 110, 120 at both ends of cartridge 1,
for example by screwing plug 42 on hollow body 46. Plug 42 is equipped
with an adapter 422 to allow connecting extracting device 4 to a carrier
gas supply. The extraction of the sample collected by means of cartridge
1 is consequently made possible directly from cartridge 1 without having
to open it, thus preserving the integrity of its content and avoiding any
risk of cross-contamination. In addition, the quick heating of cartridge
1 due to its excellent heat conductivity allows transferring immediately
and without having large dead volumes the desorbed compounds to the
separative column and to the suitable detector of the chromatograph.

[0108] Sampling and extracting device 5 according to the invention
illustrated in FIGS. 13 and 14 comprises an extracting device similar to
that of FIG. 11 connected to a body 50 comprising a suction pump 51 and
an inert gas tank 52. The inert gas can for example be helium. This
sampling and extracting device 5 operates as follows in active mode: one
places a ready-to-use cartridge 1 according to the invention in device 5,
in the same way as for extracting device 4. A filter 53 is placed on
extracting device 4 on the side opposite to body 50, suction pump 51 is
started by a control 56 to suck in the external air through filter 53,
cartridge 1 and body 50 via internal conduits. The air escapes through an
opening 54 (FIG. 14). When sampling is completed, one stops pump 51, one
removes filter 53 to replace it with a needle (not represented) with a
Luer adapter intended to be connected to an analyzer (not represented).
One opens inert gas tank 52 and, with solenoid valve 55, one puts tank 52
in communication with cartridge 1. This sampling and extracting device 5
has the advantage that it is portable and that it can be connected
directly to a portable field analyzer that allows analyzing directly the
compounds collected by cartridge 1.

INDUSTRIAL APPLICATION

[0109] In all illustrated sampling modes, it appears clearly that the
method according to the invention distinguishes itself from the known
methods by the use of one single ready-to-use single-use sampling
cartridge 1, which is entirely recyclable, preferably out of amber glass,
sealed at both ends 100, 101 by high-performance pierceable seals 110,
120, and containing preferably a universal, single-use hydrophobic solid
polymer with high adsorbent capacity, optimally arranged inside of
cartridge 1, said cartridge being moreover conditioned under inert gas.
Cartridge 1 is advantageously closed by two caps 11, 12 comprising each
an opening 111, 121 closed by said seals 110, 120, which are pierceable,
these caps 11, 12 can be sealed at both ends 100, 101, or at least one of
caps 11, 12 can be removable with respect to one of ends 100, 101 to
allow in particular performing sampling in passive mode. Cartridge 1
comprises for that purpose end pieces 102, 103, 104, 105 adapted at its
both ends 100, 101, which are integrated in glass envelope 10, 10', 10''.
In addition, cartridge 1 can be identified thanks to a unique
laser-engraved serial number and flash code, or by a label withstanding
temperatures above 400.degree. C.

[0110] After the sampling step, and without having to open cartridge 1,
unlike the known sampling devices, it is now possible to desorb
thermally, with low energy consumption and a low temperature gradient
<60.degree. C., all elements trapped on the polymer. The excellent
inertia of cartridge 1, its low thermal mass and its perfect tightness
allow obtaining a more reliable, more reproducible result, with better
sensitivity than the classical devices, without any risk of
cross-contamination.

[0111] Thus, cartridge 1 according to the invention, used both for
sampling and thermal desorption, allows ensuring: [0112] The quality of
the data collected during sampling, this data being preserved and
unalterable in the internal volume of cartridge 1, since the thermal
desorption step does not require opening cartridge 1, [0113] A constant
and identical carrier gas flow during the sampling step and the thermal
desorption step by carrier gas injection, furthering analysis accuracy,
[0114] Fast heating of cartridge 1 during thermal desorption, without
adding any interface, simplifying and reducing analysis duration.

[0115] These various advantages, added to those set out previously, allow
considering the realization of portable devices for analyzing the sampled
pollutants directly on the sampling site, allowing significant time and
costs saving and highly improved efficiency.

[0116] This description shows that the invention allows reaching the goals
defined and overcoming all drawbacks of the known systems. It allows in
particular offering a global solution ranging from the sampling to the
analysis, totally controlled, secured and optimized, which no present
solution allows reaching, as the different devices required for these
different steps come from different manufacturers.

[0117] The present invention is not restricted to the examples of
embodiment described, but extends to any modification and variant which
is obvious to a person skilled in the art.